Stoker



Nov. 13, 1934. J. HINDERER 1,930,755

STOKER Filed Sept. 6. 1932 4 Sheets-Sheet 2 1 7 ilfifiderer I Patented Nova 13, 1134 UED s'ronpn .llesse IL. Hinderer, Ganton, @hio Application September 6, 1932, Serial No. 631,795 6 cla ms. (or. Mil-45) The invention relates to stokers and more particularly to an underfeed stoker especially adapt,- ed for use in connection with a domestic furnace.

- There are many objections to the types of underfeed stokers, for domestiofurnaces particularly, which are at present in use. One objection is the manner in which the slack, powdered coal or other fuel feeds from the conveyer upward over the tuyere and grate of the furnace. Or dinarily the tuyere is of circular construction, the upper edge thereof beinglocated in a horizontal plane and the coal is fed up through the same by means of an upwardly curved, flared chamber communicating with the end of the coal feed tube.

It has been found that with such a construction there is a tendency for the coal to bank or pile higher at the rear side of the combustion chamber of the furnace, thus making it impossible to maintain an even fire bed over the entire grate.

One object of the present improvement is to provide a construction of feed chamber and tuyere which will cause the coal to be fed evenly over the entire grate so as to produce an even flrebed. This object may be attained by providing substantially a right angle in the front or upper side of the feed chamber and by providing an oval or elliptic tuyere with its major axis in a plane at right angles to the of the feed tube, the rear side. of the tuyere being higher whereby the coal is fed upward through the feed chamber and evenly over the entire grate, producing a substantially even fire bed thereon.

While various devices have been provided for shalringthe grates of stoker furnaces, both mechanically and manually, in order to sift ashes and other small particles of products of combustion through the grate into the ash pit, it is not known that there are any stolrer furnaces in use provided with means for dumping the grates whereby clinkers and other large objects may be passed through the grates into the ash pit.

It is quite inconvenient and often difiicult to manually remove clinkers and the like from the top of the grate and for this reason a further object of the improvement is to provide means for entirely dumping the grate of the improved stoker so as to empty the entire contents of the grate into the ash pit when desired. This object may be attained by providing a radial dumping grate with means for normally preventing complete dumping of the grate when the same is shaken to sift ashes therethrough.

Another objection to stoker furnaces such as are now in use is the inconvenience and difiiculty in removing ashes from the ash pit and in order to overcome the same, a further object of this improvement is to provide means for spraying the ashes with water or the like so that they may be easily removed without producing any unnecessary dust or dirt in the cellar or other place in which the furnace is located.

Another object of the improvement is to provide an air splitting device between the fan or other source of air under pressure and the furnace, with balanced dampers therein whereby the desired amount of air may be conveyed to the air chamber from which airv is fed through the tuyere to the fire bed while the remainder of the air from the fan is passed into the heating jacket or chamber of the furnace so as to assist in the creation of a circulation of air from the heating jacket through the flues and registers of p a hot air system.

A still further object of the improvement is to provide an air conditioning apparatus located in the air pressure line to the-heating jacket whereby the air is moistened before it is passed through the dues to the registers.

Another object of the improvement is to provide a manually operated valve or damper for controlling the admission of air beneath the grates from the air chamber.

The above, together with other objects which will be hereinafter pointed out or which will be apparent from an inspection of the drawings and the following description, may be attained by constructing the improved stoker in the Jinan-- ner illustrated in the accompanying drawings, in which 7 Figure 1 is a plan sectional view of a hot air furnace showing the improved stoker connected thereto;

Fig. 2, a side elevation of the same;

Fig. 3, a plan view of the grate and tuyre of the improved stoker;

Fig. 4, a side elevation of the same showing the grate rocking and dumping mechanism and the spraying device for the ash pit; I

Fig. 5,, a vertical sectional view of the mechanism shown in Fig. 4, taken as on the line 5-5, 8;

Fig. 6, a plan sectional view of the grate rocking and dumping mechanism;

Fig. 7, a detaiFsectional view of one grate bar and a portion of the grate rocking and dumping Fig. 8, a similar view showing the grate bar in the dumped position;

Fig. 9, a detail perspective view of the locking and adjusting bar for the grate shaking and dumping mechanism;

Fig. 10, an end elevation of the air conditioning apparatus;

' Fig. 11, a longitudinal sectional view through the same as on the line 11-11, Fig. 10;

Fig. 12, a vertical longitudinal sectional view through the air splitting mechanism for conveying a portion of the air from the fan to the heating jacket of the furnace;

Fig. 13, a plan sectional view of the same; and

Fig. 14, an end view of the air splitting mechanism.

Similar numerals refer throughout the drawings.

The furnace illustrated may be of any usual and well known construction comprising the out er shell or heating jacket 15 and the inner shell or fire pot 16 spaced concentrically therefrom as in usual practice and forming the heating chamber 1'7 therebetween, the combustion chamber 18 being defined within the walls of the fire pot or inner jacket 16. The outer shell 15 may be to similar parts provided with the usual firing door 19 communieating with the combustion chamber 18 and with the usual ash pit door 20 communicating with the ash pit 21, all as in usual and ordinary furnace practice.

The improved stoker mechanism to which the invention pertains includes a hopper 22 adapted to receive the fuel which may be slack, powdered coal or other finely divided fuel which is conveyed from the hopper to the furnace through the coal feed tube 23 communicating with the lower portion of the hopper and having mounted therein the coal feed screw 24 which carries the fuel therethrough.

This coaLfed screw is driven by means of any suitable gearing located in the gear case 25 driven by means of a worm upon the shaft 26 which is provided with a pulley 2'7 connected as by the belt 28 to the pulley 29 upon the shaft 30 of the motor 31. A blower fan is mounted upon the shaft 26 and located within the fan casing 32.

The inner end of the coal feed tube 23 is re- I ceived within the neck 33 of the forwardly and a trio to the lower and upwardly curved and flared coal feed chamber 34. It should be noted that the inner or upper side of this coal feed chamber is not curved concenouter side 35-thereof but forms substantially a right angle 'as shown at 36 in Fig. 5. I

The upper end of stantially circular a lower substantially circular end 3'7 of the tuyere block 38. The central opening in the tuyere block is substantially circular at its lower end as at 39 and is flared laterally at its upper end into a substantially elliptic or oval shape as indicated at 40, the-major axis of said ellipse being in a plane at right angles to the axis of the feed tube 23 and the rear side of the tuyereblock is higher than the forward side, as indicated at 41.

This oval shaped opening at'the upper portion of the tuyere block with the rear side higher than the front, together with the angular inner and upper corner 36 of the feed chamber prevents the the coal feed chamber is sub- Y coal from banking or piling over the rear portion screws or bolts 48, these d communicates with the 42 may be formed in a single casting as best shown in Fig. 5, so that the walls thereof together with the tuyere block 38 which rests upon the upper ends thereof, enclose an air chamber 43 which communicates with the blower fan as by the conduit 44. Upwardly and slightly inward- 1y angled passages 43a are formed through the tuyere block whereby air under pressure from the air chamber is directed into the fire bed.

The grate, which is of annular shape is preferably composed of a bars 45 mounted for rocking movement upon the radially disposed journals 46 mounted upon the upper ends of the brackets 4'7 which are fixed to the air jacket, at their lower ends, as by the brackets being curved outward and upward as at 49 and then inward and upward at their upper ends as at 50. The lower side of each of the gratebars 45 is provided with the radially disposed groove'51 which receives the journal 46, depending ears 52 being formed upon the grate bar at each side of said groove and pins or the like 53 being located through said ears for retaining the grate bar upon the journal.

For the purpose of shaking and dumping'the grate, means is provided for rocking each of the grate bars upon its radial journal, this means being shown as a ring 54 surrounding the air jacket and spaced therefrom, said ring being rotatably mounted and operatively connected to the grate bars.

In order to rotatably mount this ring, the same may be provided at intervals with slots 55 through which are located rollers 56 mounted upon short. radially disposed shafts 57 fixed to the air jacket 42 and provided at their outer ends with peripheral flanges 58 which prevent accidental dislodgment of the ring therefrom.

The inner end of each of the radial grate bars 45 is provided'with a centrally located depending arm 59 having an outwardly disposed, substantially horizontal stud 60 fixed thereon and received in a notch 61 in the upper edge of the grate rocking and dumping ring 54. It will thus be seen that as this ring is rotated back and forth each of the grate bars. will be radially rocked, as shown in Fig. 8, the degree to which the grate bars are moved being controlled by the amount of movement of the ring.

For the purpose of rotating the ring 54 backward and forward in order to shake or dump the grate bars, a curved link 62 is pivotally connected at its inner end, as at 63, to a depending stud 64 fixed to one side of the ring 54 as by the bracket 65 and screws or bolts 66, the outer end of this curved link having a socket 6'7 which recei'vesone -or other suitable stationary portion of the apparatus and has a rod- '71 fixed therein and extending substantially parallel to the coal feed tube,

the other end of the rod being provided with a slotted or bifurcated member '72 within which is pivoted, as at '73, the lower end of the shaking and dumping lever '74 which is pivoted intermediate its ends, as at '75, upon a bracket 76 which may be fixed in any suitable manner adjacent to the lower end of the hopper 22. The upper end of the lever '74 is located between the angular ears '77 formed at opposite ends of the bracket '78 which may be fixed to the side of the hopper 22 adjacent to the upper end thereof.

A stop bar '79, which is illustrated in detail in Fig. c, is mounted for axial rotation between the cars 77 of the bracket 78 and arranged to normally hold the lever 74 against movement and to regulate the throw of the lever for shaking or dumping the grate bars. This bar is provided at each end with an axial socket or opening 80 to receive the journal pins 81 and 82 which are journaled in the ears 77 of the bracket 78, the pin 82 being preferably provided with an angular end portion 83 by means of which the bar 79 may be rotated upon its axis so as to provide for difierent adjustments of the shaking and dumping mechanism.

The bar 79 is provided on one face, near the center thereof, with the spaced pair of lugs 84 adapted to normally engage the lever 74, as shown in Fig. 1, to hold the same against movement. on another face the bar 79 is provided with the lugs 35, located near opposite ends of the bar. When this face of the bar is turned toward the lever, the same may move between the lugs 85, giving a sufficient movement to rock the grate bars .5 only enough to shake the ashes from the fire bed into the ash pit.

By rotating the bar 79 to turn the unobstructed race 86 thereof toward the bracket 78, the lever '14 may be swung backward and forward along the entire length of the bar, being limited in its movement only by the lugs '77 upon the bracket, thus permitting the grate bars to be rocked to the position shown in Fig. 8, permitting the entire fire bed to be dumped through the grate into the ash pit, thus providing for the passage of clinkers and the like through the grate.

The invention contemplates the admission of air from the air chamber to the underside of the grates in order to assist in combustion by forcing air under pressure upward through the fire feed and for this purpose a rotatable valve 87 may be located in the lower portion of the air jacket above the bottom plate 88 thereof, and provided with radial slots or openings 89 adapted to cooperate with similar slots or openings 90 in the plate 88 in order to control the amount of air admitted to the underside of the grates, as well as to entirely cut off the same if desired.

Manually controlled means may be provided for regulating the position of the damper or valve 3'1 and as shown, this may comprise a lever 91 asby a pin 92 upon the depending end of the valve or damper shaft 93 which is journaled in the hearing 94 formed at the central portion or the plate 88. A link 95 may be pivotally connected to the end portion of the lever 91 and extended to a point where it may be con= veniently operated through the ash pit door of the furnace, as shown in Fig. 2.

Means is preferably provided for dampening the ashes in the ash pit so that they may he removed without creating an undue amount of dust and dirt in the cellar and this means may be in the form of an annular water jacket 96 located at the lower end of the air jacket 42 and surrounding the manually controlled valve or damper for admitting air from the air chamber beneath the grate. This annular water jacket may be connected to a water supply pipe 97 and is provided on its underside with a plurality of small apertures 98 adapted to direct small streams or jets of water over the ashes in the ash pit.

For the purpose of admitting air under pressure from the blower fan to the heating jacket of the furnace in order to assist in the creation of a circulation of air through the fines and registers connected with the heating jacket, an

air splitting device is located in the casing 99 which communicates with the outlet side of the fan casing 32. The air conduit it leads from said air splitting device to the air jacket 42 and a somewhat similar conduit 100 leads from said air splitting device into the lower portion of the heating chamber 17, the inner end of said conduit being cut ofi at an angle, as indicated at 101 in Fig. 1, so as to direct the air upward through the heating chamber.

The casing 991s divided into two substantially equal compartments 102 and 103 by means of the longitudinal partition wall 104, both of said compartments communicating at one end with the outlet side of the fan casing 32, while the compartment 102 communicates only with the conduit 44 and the compartment 103 with the conduit 100.

Balanced dampers 105 and 106 are located in the compartments 102 and 103 respectively, controlling the passage of air therethrough to the conduits. These dampers are both of the same construction, each being suspended from a shaft 107 connected to its upper end and journaled in the upper portion of the casing 99.

A hub 108 is fixed upon the outer end of each shaft 107 and has a rod 109 located diametrically therethrough, each end of the rod being threaded'as at 110, a counterweight 111 being mounted upon each threaded end of the rod and 11% held in adjusted position as by the lock nuts 112.

An arm 113 is fixed upon each hub, preferably at right angles to the rod 109 thereon, and is adapted to move across the face of the sector 11d provided with a plurality of;apertures 115 for 111d) selective engagement by the'pins 116 ahd 117 which are arranged to be engaged by the arm 113 to limit the opening and closing limits respectively of the damper.

With this construction the damper 105 will be my automatically adjusted by the velocity of the air passing therethrough in accordance with the condition of the fire bed and this will permit any surplus of air from the fan, not used for combustion purposes, to pass through the other compartinent 103 to the heating jacket of the furnace.

For the purpose of moistening the air in the hot air system, an air conditioning device may be provided in the casing 118 which communicates 125 with the inlet side of the fan chamber 32. The casing 118 may be provided with a removable cover 119 having aflrnob 120 for operating the same and the lower portion thereof is adapted to contain water indicated at W in Fig. 11, an outwardly inclined trough 121 communicating with the lower portion of the casing for the purpose of supplying water thereto. I

A drain opening 122 may be provided in the bottom of the casing, normally closed as by the stopper 123. A circular opening 124 is provided in each end of the casing 118 and a shaft 125 is journaled axially through the casing concentric with said openings and has a propeller wheel 126, fixed upon each end thereof, a perforate or porous cylinder 127 being fixed at its ends to said propeller wheels and arranged to dip into the water in the bottom of the casing. The outlet 128 from the casing is located at right angles to the axis of the cylinder 12'? and communicates with the inlet to the fan chamber 32.

It will thus be seen that all of the air drawn into the fan casing passes through the openings 124 of the casing 118, rotating the propeller wheels 126, and with them the perforate cylinder 15. 1

rec

,cylinder to the fan and is '127 which is continually moistened by contact municating with the upper end of the feed chamher, the upper portion of the inner surface of said tuyre block being in the form of an ellipse "Kill with its major axis at right angles to the axis of the feed tube.

2. A stoker furnace including a coal feed tube, an upwardly curved feed chamber communicating with the feed tube, and a'tuyere block communicating with the upper end of the feed chamher, the upper portion of the inner surface of said tuyre block being in the form of an ellipse with its major axis at right angles to the axis of the feed tube, and being higher on the side opposite to the feed tube than at any other point.

3. A stolrer furnace including a coal feed tube, an upwardly curved feed chamber communicating with the feed tube, the upper corner of said feed chamber adjacent to said feed tube being substantially a right angle, and a tuyere block communicating with the upper end of said feed chamber, the upper portion of' the inner surface of said tuyere block being in the form of an ellipse with its major axis at right angles to. theaxis of the feed tube.

i a. a stoker furnace including a coal feed tube,

' resume the feed tube and being higher on the side oppo site to the feed tube than at any other point.

5. A stoker furnace including an annular tuyere, means for feeding coal upward through the tuyere, an annular grate surrounding the tuyere and comprising a plurality of radial grate bars, means for rocking each grate bar upon an axis radial to the grate, a lever for operating said grate rocking means and an axially rotatable stop bar having a plurality of faces and differentially spaced lugs on various faces for limiting the movement of said grate rocking lever.

(in stoker furnace including an annular tuyere, means for feeding coal upward through the tuyere, an annular grate surrounding said tuyre and comprising a plurality of radially journaled grate bars, a ring rotatably mounted beneath the tuyere, a depending arm upon each grate bar pivotally connected to said ring, an operating lever operatively connected to said ring for rotating the ring, and an axially rotatable stop bar having a plurality of faces and differentially spaced lugs on various faces for limiting the movement of said operating lever.

JESSE L. HINDERER. 

